aurora

Imagine what it must have been like for the first human to witness an aurora. It took a while for our species to migrate from its equatorial birthplace to latitudes where auroras are common, so it was a fairly recent event geologically speaking. Still, that first time seeing the shimmers and ribbons playing across a sky yet to be marred by light pollution must have been terrifying and thrilling, and like other displays of nature’s power, it probably fueled stories of gods and demons. The myths and legends born from ignorance of what an aurora actually represents seem quaint to most of us, but it was as good a model as our ancestors needed to explain the world around them.

Our understanding of auroras needs to be a lot deeper, though, because we now know that they are not only a beautiful atmospheric phenomenon but also a critical component in the colossal electromagnetic system formed by our planet and our star. Understanding how it works is key to everything from long-distance communication to keeping satellites in orbit to long-term weather predictions.

But how exactly does one study an aurora? Something that’s so out of reach and so evanescent seems like it would be hard to study. While it’s not exactly easy science to do, it is possible to directly study auroras, and it involves some interesting technology that actually changes them, somehow making the nocturnal light show even more beautiful.

Google ‘Joan Feynman’ and you can feel the search behemoth consider asking for clarification. Did you mean: Richard Feynman? Image search is even more biased toward Richard. After maybe seven pictures of Joan, there’s an endless scroll of Richard alone, Richard playing the bongos, Richard with Arline, the love of his life.

Yes, Joan was overshadowed by her older brother, but what physicist of the era wasn’t? Richard didn’t do it on purpose. In fact, no one supported Joan’s scientific dreams more than he did, not even their mother. Before Richard ever illuminated the world with his brilliance, he shined a light on his little sister, Joan.

News comes to us this week that the famous HAARP antenna array is to be brought back into service for experiments by the University of Alaska. Built in the 1990s for the US Air Force’s High Frequency Active Auroral Research Program, the array is a 40-acre site containing a phased array of 180 HF antennas and their associated high power transmitters. Its purpose it to conduct research on charged particles in the upper atmosphere, but that hasn’t stopped an array of bizarre conspiracy theories being built around its existence.

The Air Force gave up the site to the university a few years ago, and it is their work that is about to recommence. They will be looking at the effects of charged particles on satellite-to-ground communications, as well as over-the-horizon communications and visible observations of the resulting airglow. If you live in Alaska you may be able to see the experiments in your skies, but residents elsewhere should be able to follow them with an HF radio. It’s even reported that they are seeking reports from SWLs (Short Wave Listeners). Frequencies and times will be announced on the @UAFGI Twitter account. Perhaps canny radio amateurs will join in the fun, after all it’s not often that the exact time and place of an aurora is known in advance.

Tinfoil hat wearers will no doubt have many entertaining things to say about this event, but for the rest of us it’s an opportunity for a grandstand seat on some cutting-edge atmospheric research. We’ve reported in the past on another piece of upper atmosphere research, a plan to seed it with plasma from cubesats, and for those of you that follow our Retrotechtacular series we’ve also featured a vintage look at over-the-horizon radar.

[Stef Cohen] decided to combine three different artistic mediums for her latest project. Those are painting, electronics, and software. The end goal was to recreate the aurora borealis, also known as the northern lights, in a painting.

The first step was to make the painting. [Stef] began with a shadow box. A shadow box is sort of like a picture frame that is extra deep. A snowy scene was painted directly onto the front side of the glass plate of the shadow box using acrylic paint. [Stef] painted the white, snowy ground along with some pine trees. The sky was left unpainted, in order to allow light to shine through from inside of the shadow box. A sheet of vellum paper was fixed to the inside of the glass pane. This serves to diffuse the light from the LEDs that would eventually be placed inside the box.

Next it was time to install the electronics. [Stef] used an off-the-shelf RGB LED matrix from Adafruit. The matrix is configured with 16 rows of 32 LEDs each. This was controlled with an Arduino Uno. The LED matrix was mounted inside the shadow box, behind the vellum paper. The Arduino code was easily written using Adafruit’s RGB Matrix Panel library.

To get the aurora effect just right, [Stef] used a clever trick. She took real world photographs of the aurora and pixelated them using Photoshop. She could then sample the color of each pixel to ensure that each LED was the appropriate color. Various functions from the Adafruit library were used to digitally paint the aurora into the LED matrix. Some subtle animations were also included to give it an extra kick.

Unless you live way up in Canada, it’s not very likely that those gorgeous coronal mass ejections will collide with the atmosphere above your home. If they do, it’s a rare occurrence you wouldn’t want to miss. This is why [James] devised of a special alarm that would notify him when the Northern Lights may be visible in his neck of the woods. And what’s a better aurora alarm than a simulated aurora light show for your room?

[James] uses a Raspberry Pi to check data from Aurora Watch UK at Lancaster University for local activity. If the forecast reads that there may be some light above his home town in northern England, it triggers a NeoPixel LED strip to scroll through the color values of an actual aurora PNG image. This produces the same sporadic shifting of colors for a proximal ambient indoor lighting effect… though slightly less dramatic than the real thing. You can take a look at his Python script on github if you feel inspired.

In the hopes of getting a heads up on when the aurora borealis will be visible from his back yard, [Alex] built a magnetometer to measure disruptions in Earth’s magnetic field. The build is extremely simple, too. It’s amazing what you can build with a few components and a trip to the dollar store.

The design or [Alex]’s project is called a torsion magnetometers. In this setup, two mirrors are affixed to a permanent magnet connected to a string. A laser is shone onto the mirror and is reflected back to an array of sensors. In [Alex]’s case he used a simple laser pointer and a pair of photoresistors encased in a PVC tube.

[Alex] has been running his magnetometer in his back yard for over a month now and has the data to prove it. Luckily for [Alex], those graphs he has been generating may get a little more interesting. A coronal mass ejection is coming our way and is expected to hit today around 22:30 UTC. We’ll go outside to look for an aurora, but we’re sure [Alex] will be glued to his laptop tonight.

Check out the CGI visualization of [Alex]’s magnetometer after the break

Stanton has released a new controller peripheral for laptop DJ’s. DaScratch is a USB connected MIDI device designed to emulate record interactions. It features a large touch area where the user can make scratching, sliding, and button pressing motions. The compact device has presets for software like Traktor, Serato, and Ableton Live, but can work with anything that supports MIDI. Multiple units can be paired together using magnets.

As the video below shows, there are quite a few different interactions possible. We really want to see a teardown of this device though. We get the distinct feeling that it’s designed to look more impressive than the underlying hardware actually is. Continue reading “DaScratch multitouch DJ interface”→